I've found that the Carter carbs have problems with the E10 gas that we have around here. They grow a white slime inside the fuel bowls that can plug up passages. I haven't had the same issue with Holley carbs so I think it is a chemical reaction.

When I had a Carter carb (actually mfg by Weber in my case) on my truck I had to open it up a couple of times each winter and clean it out. It was only the winter gas mix that caused problems, not the summer gas.